The present invention generally relates to electrical technology and more specifically, to a method and apparatus for protection switching.
Conventional communications systems are configured in a rack with slots coupled together by a bus on a backplane. Working modules are inserted into the slots. Each working module includes equipment for transmitting data at either high or slow speeds. Thus, a single rack may be used to transmit high and slow speed data.
Conventionally, the racks have a fixed number of slots into which working modules for high and slow speed data transmission may be inserted. Conventional communications systems are also preferably designed to permit uninterrupted operation. For example, if a working module, facilitating high speed data transmission, fails, the communications system facilitates high speed data transmission by routing the failed working module to another working module through a protection bus by actuating a protection card. The protection card must be inserted into a specific slot in the rack.
Additionally, the protection card protects only a fixed number of working modules, otherwise known as a protection group. The conventional protection group has a fixed protection ratio. The protection ratio is the ratio of the number of working modules to protection cards. Conventionally, the protection group may comprise no more or less than a specific number working modules and one protection card. Furthermore, the working modules in a protection group must be of a predetermined type, such as for high or low speed data transmission.
Because they use protection groups with fixed protection ratios and predetermined types, the racks have limited configuration alternatives. Therefore, there is a need for a rack permitting flexible configuration.
The present invention solves the above-mentioned problems in the art and other problems which will be understood by those in the art upon reading and understanding the present specification. The present invention provides a method and apparatus for protection switching for enhancing the flexibility of an electrical system.
One embodiment of an apparatus of the present invention comprises a protection group. The protection group includes components, and a signal bus, including segments and connectors, that couple the components. The components also include a plurality of working components, and a protection component. Each connector is included in a working component. Each segment couples two adjacent components. The signal bus is terminated by the protection component.
In another embodiment, the signal bus comprises a plurality of signal buses, each including segments and connectors, that couple the components. In yet another embodiment, a control bus couples the components. In a further embodiment, the apparatus is a rack with slots, and the components are modules inserted into the slots.
One embodiment of a method of the present invention comprises generating a first signal from a plurality of working components. The first signal is analyzed by a protection component to determine if any working component is not functioning. The protection component transmits a second signal to the plurality of the working components to turn off an improperly functioning working component. Data signals are routed by coupling the improperly functioning working component through a signal bus to the protection component. The data signals are processed by the protection component. It is an advantage of the present invention that it provides flexible configurability.